John Wood Polaris Commercial High-Efficiency - Manual (Page 15)

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• Do not use with piping that has been treated with
chromates, boiler seal or other chemicals and do not
add any chemicals to the water heater piping.
• If the space heating system requires water temperatures
in excess of 120°F (48.9°C), a mixing valve (provided)
must be installed per the manufacturer’s instructions
in the potable hot water supply to limit the risk of scald
injury.
• Pumps, valves, piping and fittings must be compatible
with potable water.
• A properly installed flow control valve is required to pre-
vent thermosiphoning. Thermosiphoning is the result
of a continuous flow of water through the air handler
circuit during the off cycle. Weeping (blow off) of the
temperature and pressure relief valve (T & P) or higher
than normal water temperatures are the first signs of
thermosiphoning.
• The hot water line from the water heater should be ver-
tical past any mixing valve or supply line to the heating
system to remove air bubbles from the system.
• Do not connect the water heater to any system or
components previously used with non-potable water
heating appliances when used to supply potable water.
Storage Tank Installation
When installing the Polaris® with a storage tank, see figure
18 for piping suggestions.
Solar Installation
If this water heater is used as a solar storage heater or as
a backup for the solar system, the water supply tempera-
tures to the water heater tank may be in excess of 120°F
(48.9°C). A mixing valve must be installed in the water sup-
ply line to limit the supply temperature to 120°F (48.9°C).
Note: Solar water heating systems can often supply water
with temperatures exceeding 180°F (82.2°C) and may
result in water heater malfunction.
Figure 17: Air Handler Piping Installation
Mixing Valve
Metal Drain Pan
6” (15.2cm)
Air Gap Max.
Adequate Drain